The problem of diagnosing the accident rate of trees in an urban environment

Identification of emergency trees is an urgent practical task, which is primarily important for the conditions of the urban environment. The methodological basis for solving this problem began to form quite a long time ago, but due to biological limitations, this issue cannot be solved unambiguously at the present time. The article considers the existing approaches to the identification of emergency trees and discusses the biological prerequisites for their use and possible limitations. It is shown that the accident rate of trees can be caused by a numbers of environmental and physiological factors, among which the greatest practical significance has the level of development of hidden stem rot. However, the crown windage and the nature of the wind load on the tree trunk in a landscape can cause different accidents of the trunk at the same level of dynamic wind load. The accident rate of a tree is poorly related to its pathological condition, for the full identification of emergency trees, only instrumental diagnostics is possible. Methods of instrumental diagnostics, as well as methods to reduce the accident rate of trees are discussed. As a typical example, the results of the identification of emergency trees in one of the parks of the Moscow region are presented according to the diagnostic data of the level of trunk rot development using the Pressler increment borer.